ATLANTA, GA - Scientists from the laboratory of Asher A. Chanan-Khan, MD, Department of Medicine, Roswell Park Cancer Institute (RPCI), will present preliminary laboratory and clinical results of new therapies for chronic lymphocytic leukemia (CLL) at the 47^th Annual Meeting of the American Society of Hematology, December 10-13, Atlanta, GA.

Chronic lymphocytic leukemia, one of the most common types of adult leukemia, affects approximately 50,000 patients nationwide. A cancer of the mature lymphocytes, CLL compromises the immune system predisposing patients to infectious complications. CLL remains incurable with all patients eventually relapsing with leukemia. These patients have limited treatment options. An estimated 14,330 new cases will be diagnosed in 2005.

“In Vivo Evaluation of Immunomodulating Effects of Lenalidomide (L) on Tumor Cell Microenvironment as a Possible Underlying Mechanism of the Antitumor Effects Observed in Patients with Chronic Lymphocytic Leukemia (CLL). (Abstract # 2975)

Embargoed until Monday, December 12 – 10:30 am

Hall B4 - Georgia World Congress Center

Clinical anti-leukemic activity of lenalidomide (L) will be reported for the first time in an RPCI group of patients diagnosed with CLL. The underlying mechanism of its antitumor activity remains undetermined. In vitro evaluation does not suggest a direct apoptotic effect of L on the malignant CLL cells and thus support the hypothesis that the anti-leukemic effect noted in the clinical trial (reported separately – Abstract # 447) is most likely from in vivo modulation of the tumor microenvironment as demonstrated from changes in the cytokine milieu and the cellular immune response. Collectively these changes may be responsible for the immune modulating properties of L and the resultant anti-CLL activity in patients.

“Thalidomide (T) in Combination with Fludarabine (F) as Initial Therapy for Patients with Treatment Naïve Chronic Lymphocytic Leukemia (CLL): Preliminary Results of a Phase I/II Clinical Trial.” (Abstract # 2974)

Embargoed until Monday, December 12 – 10:30 am

Hall B4 - Georgia World Congress Center

In this Phase I/II clinical trial, thalidomide (T) resulted in a higher overall response rate when given in combination with fludarabine when compared to fludarabine alone. Thirteen patients completed six months of therapy. Nine (69.2%) achieved complete responses and four (30.7%) had partial remissions. The combination was well tolerated with manageable toxicity. Completion of this ongoing study will identify the role of this new combination in patients with CLL.

T is an immunomodulatory agent reported to exert antitumor activity in CLL. This study targeted the tumor microenvironment with T, thereby interrupting the growth promoting signals and predisposing CLL cells to enhanced activity of fludarabine resulting in improved clinical responses.

“Results of Phase II Study of Lenalidomide (L) (Revlimid®) in Patients with Relapsed or Refractory Chronic Lymphocytic Leukemia (CLL) (Abstract # 447)

Embargoed until Monday, December 12 - 2 pm

Hall B4 - Georgia World Congress Center

This is the first study to report clinical activity of L in patients with CLL. In the phase II clinical trial, 29 patients with relapsed or refractory CLL received 25 mg of L for 21 days, followed by seven days of rest on a 28-day cycle. Responses for 17 out of 29 patients were evaluated after a maximum of 12 months. Complete remissions were noted in two (11.7%) patients; partial remissions in nine (52.9%) patients and five (29.4%) patients had stablized disease. These findings are encouraging and provide evidence of the anti-CLL activity of lenalidomide. Longer follow-up data will determine the durability of responses noted to date.

L is one of a new class of oral cancer drugs that are chemically similar to thalidomide, but are more potent in the laboratory and appear to lack some of the more common side effects of thalidomide.

The American Society of Hematology’s (ASH) annual meeting provides a forum for nearly 20,000 clinicians, scientists and others from around the world to discuss the latest developments in scientific research in hematology. ASH strives to further the understanding, diagnosis, treatment, and prevention of disorders affecting the blood, bone marrow, and the immunologic, hemostatic and vascular systems, by promoting research, clinical care, education, training, and advocacy in hematology.

Roswell Park Cancer Institute, founded in 1898, is the nation’s first cancer research, treatment, and education center and is the only National Cancer Institute-designated comprehensive cancer center in Upstate New York. RPCI is a member of the prestigious National Comprehensive Cancer Network, an alliance of the nation’s leading cancer centers. For more information, visit RPCI’s website at www.roswellpark.org, call 1-877-ASK-RPCI (1-877-275-7724) or email askrpci@roswellpark.org.